title: Expression, purification, crystallization and preliminary X-ray analysis of the DNA-binding domain of Rhodobacter capsulatus MopB.
abstract: The LysR-type regulator MopB represses transcription of several target genes (including the nitrogen-fixation gene anfA) in Rhodobacter capsulatus at high molybdenum concentrations. In this study, the isolated DNA-binding domain of MopB (MopBHTH) was overexpressed in Escherichia coli. Purified MopBHTH bound the anfA promoter as shown by DNA mobility-shift assays, demonstrating the function of the isolated regulator domain. MopBHTH was crystallized using the sitting-drop vapour-diffusion method in the presence of 0.2 M lithium sulfate, 0.1 M phosphate/citrate pH 4.2, 20%(w/v) PEG 1000 at 291 K. The crystal belonged to space group P3(1)21 or P3(2)21, with unit-cell parameters a=b=61.84, c=139.64 Å, α=β=90, γ=120°, and diffracted to 3.3 Å resolution at a synchrotron source.
authors.affiliation: Lehrstuhl für Biologie der Mikroorganismen, Fakultät für Biologie und Biotechnologie, Ruhr-Universität Bochum, 44780 Bochum, Germany.
authors.forename: Alexandra
authors.initials: A
authors.lastname: Müller
authors.forename: Christine
authors.initials: C
authors.lastname: Schlicker
authors.forename: Maria
authors.initials: M
authors.lastname: Fehringer
authors.forename: Bernd
authors.initials: B
authors.lastname: Masepohl
authors.forename: Eckhard
authors.initials: E
authors.lastname: Hofmann
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification*; D003460:Crystallization; D018360:Crystallography, X-Ray; D026901:Membrane Transport Proteins / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification*; D008969:Molecular Sequence Data; D008982:Molybdenum / Q000378:metabolism; D016354:Rhodobacter capsulatus / Q000737:chemistry*
chemical_list: D001426:Bacterial Proteins; D026901:Membrane Transport Proteins; C081167:mopB protein, Rhodobacter capsulatus; D008982:Molybdenum